Terahertz Reflection Spectroscopy of Aqueous NaCl and LiCl Solutions

Article

Abstract

We present spectroscopic measurements of the full dielectric function of aqueous solutions of sodium chloride and lithium chloride at concentrations approaching their solubility limits at room temperature. We find that the dielectric properties of the two salts are rather different at THz frequencies. Whereas both the real and imaginary part of the permittivity of NaCl increases with concentration, we see that the imaginary part of the permittivity of LiCl (related to the absorption) decreases with increasing salt concentration. We relate these changes to the behavior of slow and fast Debye relaxation processes in the solutions.

Keywords

Terahertz time-domain spectroscopy Electrolyte solution Debye relaxation Dielectric function 

References

  1. 1.
    L. Thrane, R. H. Jacobsen, P. Uhd Jepsen, and S. R. Keiding, “THz reflection spectroscopy of liquid water,” Chemical Physics Letters 240, 330–333 (1995).CrossRefGoogle Scholar
  2. 2.
    J. T. Kindt, and C. A. Schmuttenmaer, “Far-infrared dielectric properties of polar liquids probed by femtosecond terahertz pulse spectroscopy,” Journal of Physical Chemistry 100, 10373–10379 (1996).CrossRefGoogle Scholar
  3. 3.
    S. Schrödle, B. M. Fischer, H. Helm, and R. Buchner, “Picosecond dynamics and microheterogenity of water + dioxane mixtures,” Journal of Physical Chemistry A 111, 2043–2046 (2007).CrossRefGoogle Scholar
  4. 4.
    D. A. Turton, J. Hunger, A. Stoppa, G. Hefter, A. Thoman, M. Walther et al., “Dynamics of imidazolium ionic liquids from a combined dielectric relaxation and Optical Kerr Effect study: Evidence for mesoscopic aggregation,” Journal of the American Chemical Society 131, 11140–11146 (2009).Google Scholar
  5. 5.
    H. Yada, M. Nagai, and K. Tanaka, “Origin of the fast relaxation component of water and heavy water revealed by terahertz time-domain attenuated total reflection spectroscopy,” Chemical Physics Letters 464, 166–170 (2008).CrossRefGoogle Scholar
  6. 6.
    H. Yada, M. Nagai, and K. Tanaka, “The intermolecular stretching vibration mode in water isotopes investigated with broadband terahertz time-domain spectroscopy,” Chemical Physics Letters 473, 279–283 (2009).CrossRefGoogle Scholar
  7. 7.
    U. Møller, D. G. Cooke, K. Tanaka, and P. Uhd Jepsen, “Terahertz reflection spectroscopy of Debye relaxation in polar liquids,” Journal of the Optical Society of America B 19, A113–A125 (2009).Google Scholar
  8. 8.
    R. Buchner, G. T. Hefter, and P. M. May, “Dielectric relaxation of aqueous NaCl solutions,” Journal of Physical Chemistry A 103, 1–9 (1999).CrossRefGoogle Scholar
  9. 9.
    W. Wachter, S. Fernandez, R. Buchner, and G. Hefter, “Ion association and hydration in aqueous solutions of LiCl and Li2SO4 by dielectric spectroscopy,” Journal of Physical Chemistry B 111, 9010–9017 (2007).CrossRefGoogle Scholar
  10. 10.
    A. K. Lyashchenko and A. Yu. Zasetsky, “Complex dielectric permittivity and relaxation parameters of concentrated aqueous electrolyte solutions in millimeter and centimeter wavelength ranges,” Journal of Molecular Liquids 77, 61–75 (1998).CrossRefGoogle Scholar
  11. 11.
    A. Peyman, C. Gabriel, and E. H. Grant, “Complex permittivity of sodium chloride solutions at microwave frequencies,” Bioelectromagnetics 28, 264–274 (2007).CrossRefGoogle Scholar
  12. 12.
    Y.-Z. Wei and S. Sridhar, “Dielectric spectroscopy up to 20 GHz of LiCl/H2O solutions,” Journal of Chemical Physics 92, 923–928 (1989).CrossRefGoogle Scholar
  13. 13.
    D. Grischkowsky, S. Keiding, M. van Exter, and Ch. Fattinger, “Far-infrared time-domain spectroscopy with terahertz beams of dielectrics and semiconductors,” Journal of the Optical Society of America B 7, 2006–2015 (1990).CrossRefGoogle Scholar
  14. 14.
    F. E. Doany, D. Grischkowsky, and C.-C. Chi, “Carrier lifetime versus ion-implantion dose in silicon on sapphire,” Applied Physics Letters 50, 460–462 (1987).CrossRefGoogle Scholar
  15. 15.
    P. Uhd Jepsen and S. R. Keiding, “Radiation patterns from lens-coupled terahertz antennas,” Optics Letters 20, 807–809 (1995).CrossRefGoogle Scholar
  16. 16.
    J. Van Rudd and D. M. Mittleman, “Influence of substrate-lens design in terahertz time-domain spectroscopy,” Journal of the Optical Society of America B 19, 319–330 (2002).CrossRefGoogle Scholar
  17. 17.
    M. T. Reiten, S. A. Harmon, and R. A. Cheville, “Terahertz beam propagation measured through three-dimensional amplitude profile determination,” Journal of the Optical Society of America B 20, 2215–2225 (2003).CrossRefGoogle Scholar
  18. 18.
    M. T. Reiten and R. A. Cheville, “Effect of spherical aberration and surface waves on propagation of lens-couples terahertz pulses,” Optics Letters 30, 673–675 (2005).CrossRefGoogle Scholar
  19. 19.
    P. Uhd Jepsen, U. Møller, and H. Merbold, “Investigation of aqueous alcohol and sugar solutions with reflection terahertz time-domain spectroscopy,” Optics Express 15, 14717–14737 (2007).CrossRefGoogle Scholar
  20. 20.
    E. R. Malinowski, P. S. Knapp, and B. Feuer, “NMR studies of aqueous electrolyte solutions. I. Hydration number of NaCl determined from temperature effects on proton shift,” Journal of Chemical Physics 45, 4274–4279 (1966).CrossRefGoogle Scholar
  21. 21.
    J. L. Green, A. R. Lacey, and M. G. Sceats, “Determination of the total hydration number of a LiCl cation-anion pair via collective proton motions,” Chemical Physics Letters 134, 385–391 (1987).CrossRefGoogle Scholar
  22. 22.
    Y.-Z. Wei, A. C. Kumbharkhane, M. Sadeghi, J. T. Sage, W. D. Tian, P. M. Champion et al., “Protein hydration investigations with high-frequency dielectric spectroscopy,” Journal of Physical Chemistry 98, 6644–6651 (1994).CrossRefGoogle Scholar
  23. 23.
    T. Arikawa, M. Nagai, and K. Tanaka, “Characterizing hydration state in solution using terahertz time-domain attenuated total reflection spectroscopy,” Chemical Physics Letters 457, 12–17 (2008).CrossRefGoogle Scholar
  24. 24.
    M. Heyden, E. Brundermann, U. Heugen, G. Niehues, D. M. Leitner, and M. Havenith, “Long-range influence of carbohydrates on the solvation dynamics of water - Answers from terahertz absorption measurements and molecular modeling simulations,” Journal of the American Chemical Society 130, 5773–5779 (2008).CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  1. 1.DTU Fotonik - Department of Photonics EngineeringTechnical University of DenmarkKgs. LyngbyDenmark
  2. 2.Institute of Applied PhysicsUniversity of BernBernSwitzerland

Personalised recommendations